MC68349 Datasheet, PDF (5/7 Pages) Motorola, Inc – HIGH PERFORMANCE INTEGRATED PROCESSOR

Freescale Semiconductor, Inc.
ON-CHIP PERIPHERALS
To improve total system throughput and reduce parts count, board size, and cost of system implementation,
the M68300 family integrates on-chip, intelligent peripheral modules and typical glue logic. These functions
on the MC68349 include a DMA controller, a serial module, and the system integration module.
The processor communicates with these modules over the on-chip intermodule bus (IMB). This backbone of
the chip is similar to traditional external buses with address, data, clock, interrupt, arbitration, and
handshake signals. Because bus masters (like the CPU32+ and DMA), peripherals, and the SIM49 are all
on the chip, the IMB ensures that communication between these modules is fully synchronized and that
arbitration and interrupts can be handled in parallel with data transfers, greatly improving system
performance. Internal accesses across the IMB can be monitored from outside the chip, if desired.
DMA MODULE
The MC68349 contains a high-speed 32-bit DMA controller to quickly move large blocks of data between
internal peripherals, external peripherals, or memory without processor intervention. The DMA module
consists of two, independent, programmable channels. Each channel has separate request, acknowledge,
and done signals. Each channel can operate in a single-address (flyby) or a dual-address mode. Each
channel supports 32 bits of address and 8, 16, or 32 bits of data.
SERIAL MODULE
Most digital systems use serial I/O to communicate with host computers, operator terminals, or remote
devices. The MC68349 contains a two-channel, full-duplex universal synchronous/asynchronous
receive/transfer (USART). An on-chip baud rate generator provides standard baud rates up to 76.8k baud
independently to each channel's receiver and transmitter. The module is functionally equivalent to the
MC68681/MC2681 dual universal asynchronous receive/transfer (DUART).
SYSTEM INTEGRATION MODULE
The MC68349 system integration module (SIM49) handles a wide array of functions, eliminating the need
for much of the glue logic which typically supports the microprocessor and its interface with peripherals and
external memory. The SIM49 includes:
• External Bus Interface—Transfers information between the CPU32+ or DMA controller and external
memory or peripherals by providing up to 32 address lines and 32 data lines.
• System Configuration and Protection—Achieves maximum system protection by providing various
monitors and timers to prevent system lockup, recover from catastrophic failure, exit infinite loops,
provide refresh, etc.
• Clock Synthesizer—Generates the clock signals used by all internal operations as well as a clock
output used by external devices.
• Chip Select and Wait State Generation—Offers four programmable chip selects which provide signals
to enable external memory and peripheral circuits and create all external handshaking and timing
signals.
• Interrupt Control—Provides up to seven discrete interrupt inputs for external devices.
• IEEE 1149.1 Test Access Port (JTAG)—Aids in system diagnostics by providing dedicated, user-
accessible test logic that is fully compliant with the IEEE 1149.1 standard for boundary scan testability.
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MC68349 PRODUCT INFORMATION
MOTOROLA
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